(a) Field of the Invention
The present invention relates to a one-solution type thermosetting resin composition for a protective film of a color filter, and a color filter fabricated using the same. More particularly, the present invention relates to a one-solution type thermosetting resin composition being capable of improving flatness, close-contacting property, transmission properties, heat resistance, chemical resistance, and storage stability of a protective film of a color filter, and a color filter fabricated using the same.
(b) Description of the Related Art
In general, a liquid crystal display (LCD) and an image sensor require a color filter including a protective film on its surface for the purpose of flatness improvement and protection. This surface protective film should have sufficient heat resistance and chemical resistance to endure a process for developing optical transparency and forming a transparent conducting film. In addition, a one-solution type thermosetting resin composition should be capable of being stored for an extended period of time at a normal temperature, and have sufficient storage stability at a high temperature in order to diminish a waiting period to reach room temperature before use.
Materials for a protective film of a color filter and a method of forming the same are conventionally well-known. For example, Japanese Patent Laid-open Pyong 1-134306 discloses a protective film of a color filter that was prepared by using glycidylmethacrylate as a main component, Japanese Patent Laid-open Soh 62-163016 discloses a protective film of a color filter including polyimide as a main component, and Japanese Patent Laid-open Soh 63-131103 discloses a protective film of a color filter including a mixture of a melamine resin and an epoxy resin as a main component.
In addition, many other examples of a composition for a protective film of a color filter have been disclosed, which were prepared to have high reliability such as through adhesion strength, heat resistance, chemical resistance, water resistance, and the like, by using an epoxy resin. For example, Japanese Patent Laid-open Pyong 08-050289 discloses a curable resin composition prepared by using a phenol-based curing agent with a glycidylmethacrylate polymer. Further, Japanese Patent Laid-open Pyong 08-201617 discloses a resin composition for a transparent film including an epoxy resin, a curing agent, and an organic solvent. The curing agent includes a reactant of a styrene maleic anhydride copolymer and an amine series.
In general, since an epoxy resin quickly reacts with a curing agent, it is commonly prepared as a two-component thermosetting resin that is used by mixing a main material and a curing agent, rather than as a one-solution type thermosetting resin. Since the two-component thermosetting resin is difficult to handle, there are difficulties in mass production of the same.
However, no marketable one-solution type epoxy having long-term storage stability at room and high temperatures as well as resin transparency, heat resistance, acidic resistance, and alkali resistance has been produced. Japanese Patent Laid-open No. 2001-091732 discloses technology for improving storage stability by protecting a multi-functional carbonic acid compound with vinylether and the like, but it has problems of a complex manufacturing process and a low yield of the protection-treated epoxy resin.